Botulinum toxin is made from a type of bacteria. It is toxic to the nerves. Another name for it is bacterial neurotoxin. An injection puts this toxin into muscle. There, it blocks the chemical signal from the nerves to muscles. This will decrease the muscle contraction (tightening).

There are several types and brands of this toxin. Examples include Botox, Dysport, and Reloxin, which are formulations of botulinum toxin type A. Myobloc is another brand, but it is a formulation of botulinum toxin type B. These products are used for cosmetic and medical reasons.This injection process is often called botox injection , although any brand of the botulinum toxin may be used.